How do you structure your library to incorporate codegen generated C++ code and custom C++ code for Fabric components?

[sidorchukandrew]

I'm working on a library with Fabric components and Turbo Modules. Some of the Fabric components can use the default generated C++ code because height and width measurements will be provided from the JS side. Other components have intrinsic sizing that the native component should communicate to Yoga.

In the new architecture, this has to be done via ShadowNodes in C++. I've found examples like react-native-slider that declare the native component to be interfaceOnly: true. This means codegen won't generate all the C++ code for it. It is manually written and added to the library.

How do I setup the C++ code to use both the Codegen generated code (like ComponentDescriptors, EventEmitters, Props, ShadowNodes and States) and manual written C++ code for components that need to provide sizing to Yoga?

The two thoughts I have are:

1. Add all my custom code to the auto-generated files. But my custom code would get overwritten every time codegen runs.
2. Somehow import the auto-generated code into my custom code

[sidorchukandrew]

I'm assuming that CMakeLists.txt will need to be edited to import all the correct files.

[sidorchukandrew]

Based on react-native-slider's CMakeLists.txt, it looks like it's pulling in all the auto-generated C++ code and the manual C++ code.

Codegen generates two files called <SpecName>.cpp and <SpecName>.h at the root of the generated directory. I think I should cut/paste these two files to my custom code directory but then expand on them to include all my custom ComponentDescriptors too. Every time codegen runs, I should reconcile the new things in those files and place them in my files.

Does any of this sound right or wrong?

[sidorchukandrew]

I think I got the setup correct.